#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n;
    cin >> n;
    vector<int> a(n), b(n);
    for(auto& x : a) cin >> x;
    for(auto& x : b) cin >> x;
    map<int, vector<int>, greater<int>> mp;
    for(int i = 0; i < n; i++) mp[a[i] - b[i]].push_back(i + 1);
    cout << mp.begin()->second.size() << endl; 
    for(auto x : mp.begin()->second) {
        cout << x << ' ';
    }
    cout << '\n';
}

int main() {
    int t;
    cin >> t;
    while(t--) solve();
    return 0;
}